THYKEOID GLAND OF THE TELEOSTS 



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Fig. 5. A to C. Sections through the thyreoid gland of Salmo mykiss. A, 

 in the aortic bifurcation; B, closely anterior to the second; C, at the third bran- 

 chial arteries. D. Section through the thyreoid gland of Cristivomer at the 

 second branchial arteries. 



The follicles do not lie directly on the first branchial arter- 

 ies, but are grouped around large veins or lymph sinuses, the 

 dorsal follicles being much larger than the ventral ones. Behind 

 the first arterial branches the dispersion of folhcles is very much 

 reduced. They are forced away from the dorsal region by the 



